Cyber Resilience

CVE-2026-43384

Critical

Published: 08 May 2026

Published
08 May 2026
Modified
26 May 2026
KEV Added
—
Patch
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CVSS Score v3.1 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0046 36.5th percentile
Risk Priority 70 floored blend · peak EPSS

Summary

CVE-2026-43384 is a critical-severity an unspecified weakness vulnerability in Linux Linux Kernel. Its CVSS base score is 9.8 (Critical).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploit Public-Facing Application (T1190); ranked at the 36.5th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

In the Linux kernel, the following vulnerability has been resolved: net/tcp-ao: Fix MAC comparison to be constant-time To prevent timing attacks, MACs need to be compared in constant time. Use the appropriate helper function for this.

CWE(s)
NVD-CWE-noinfo

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1600 Weaken Encryption Defense Impairment
Adversaries may compromise a network device’s encryption capability in order to bypass encryption that would otherwise protect data communications.
attack.mitre.org →
Why these techniques?

Remote kernel networking flaw in TCP-AO MAC handling directly enables remote exploitation of public-facing systems (T1190) and exploitation of a cryptographic timing side-channel weakness (T1600).

Confidence: MEDIUM · MITRE ATT&CK Enterprise v19.0

Affected Assets

linux
linux kernel
7.0 · 6.7 — 6.12.78 · 6.13 — 6.18.19 · 6.19 — 6.19.9

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References